This Phase II proposal describes a plan to build prototype speech processors capable of driving a new generation of high-density multi-electrode cochlear implants. Because the new implant electrodes will have 60 or more channels, they will require that the total amount of speech information be transmitted to the electrodes at an aggregate rate higher than that currently available in available speech processors. In addition, the proposal describes attempts to perhaps realize additional frequency selectivity and control over the signals delivered to individual electrodes and specific places along the cochlear partition. These devices will be made available to researchers who can then test the possible advantages of the new implant capabilities. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE